Upheld: Termination for failed random drug test of trucker

Random drug and alcohol testing remains one of the most contentious issues in Canadian employment law.

In McCarthy v. Bison Transport Inc., 2026 ONSC 3729, the Ontario Superior Court of Justice addressed the consequences of a second positive random drug test for a long-haul trucker operating on cross-border routes.

The decision provides important guidance on the intersection of random testing policies, safety-sensitive positions,
and human rights obligations.

Random testing in cross-border transportation

The plaintiff was employed as a long-haul driver by Bison Transport Inc., one of Canada’s largest trucking companies. As a driver operating tractor/trailer units on designated routes (including cross-border routes between Canada and the United States), he held a safety-sensitive position. Notably, cross-border trucking operations are subject to U.S.  Department of Transportation regulations that mandate random drug and alcohol testing for commercial vehicle operators. 

Bison had a drug and alcohol testing policy that included random testing. This policy was clearly communicated to employees. During a five-day orientation session in October 2013, the driver signed acknowledgements confirming his understanding of the policy, including the “Rules of Conduct, including Drug and Alcohol Policy Acknowledgment,” which stated that a “Zero Tolerance Policy will be applied to violators” and that violations could lead to “disciplinary action up to and including termination of employment.”

In November 2014, the driver failed a random drug test, testing positive for cannabis. He was placed on unpaid leave and referred to a substance abuse professional, who advised Bison that the driver does not have a current problem with substance abuse/addiction. He completed the required educational programming, passed a return-to-work test, and resumed driving. He was issued a written warning stating that if he had “any failed drug or alcohol tests he could face immediate termination.”

In October 2017, the driver failed a second random drug test, again testing positive for cannabis. When asked to explain, he admitted to marijuana use, describing it as “single-time” casual use “to get close to a female individual.” Having regard to the safety-sensitive nature of his position, his clear understanding of the policy, the repetitive nature of the breach, and the absence of any addiction or dependency issue, Bison terminated his employment for cause.

The plaintiff brought a wrongful dismissal claim alleging breach of human rights legislation but did not challenge the legality of Bison’s random testing program. Indeed, he acknowledged that random drug testing of commercial drivers is a legitimate means of promoting road safety. The court dismissed the claim and upheld the termination.

What the court decided

Termination for cause following random testing. The court upheld Bison’s termination of the plaintiff following his second failed random drug test. Relying on a leading case, Milazzo v. Autocar Connaisseur Inc., 2003 CHRT 37, the court accepted that random drug testing of commercial drivers may serve a legitimate road safety objective.

Citing Hampton Securities Limited v. Dean, 2018 ONSC 101, it confirmed that termination for cause for a breach of a drug and alcohol testing policy (including random testing) requires the employer to prove that the policy is well-known, consistently enforced, and the consequences proportionate. In the circumstances of this case, the court found that the following factors supported cause:

• the plaintiff held a safety-sensitive position subject to mandatory random drug testing under U.S. DOT regulations
• the employer’s random drug and alcohol testing policy was clearly communicated during orientation
• the employee understood that a second failed random test could result in termination
• the employer applied the random testing policy consistently across its workforce.

Human rights claim

The plaintiff’s human rights claim was dismissed. The court held that a positive random drug test alone does not establish a disability requiring accommodation. The duty to accommodate arises only where a disability actually exists or is reasonably perceived.

Here, following both failed random tests, the driver was assessed by a substance abuse professional as not having an addiction, and he ultimately withdrew his disability claim in the course of the litigation.

Without a disability, the duty to accommodate did not arise, and Bison was entitled to proceed with termination following the second positive random test.

Key takeaways

This decision provides important guidance for employers operating random drug testing programs, particularly in safety-sensitive and regulated industries.

1. Random testing accepted in the cross-border transportation context: Cross-border trucking operations are subject to U.S. Department of Transportation regulations, which require random drug and alcohol testing for commercial motor vehicle operators and prohibit safety-sensitive functions following a failed test until evaluation, treatment, and reinstatement. This regulatory mandate provided a foundation for Bison’s random testing program that the plaintiff did not challenge. The decision does not revisit the issues considered in the Supreme Court of Canada’s decision in Communications, Energy and Paperworkers Union of Canada, Local 30 v. Irving Pulp & Paper, Ltd., 2013 SCC 34, because the plaintiff did not challenge the validity of the employer's random testing program. Instead, the Court focused on whether termination for cause was justified in the circumstances.

2. Clear policies and consistent enforcement are essential: The success of Bison’s approach rested on clear policy communication, signed acknowledgements, and consistent enforcement. Employers with random testing programs whether mandated by U.S. DOT regulations for cross-border operations, required by third-party site owners, or adopted in safety-sensitive workplaces should ensure their policies meet these standards. The permissibility of random testing continues to be tested in recent decisions. 

3. A second-chance approach strengthens the employer’s position: Bison’s practice of referring first-time test failures to a substance abuse professional, requiring educational programming, and issuing a clear written warning before termination for a second offence provided a defensible framework. This approach demonstrated good faith and helped distinguish recreational users from employees with addictions who may require accommodation.

4. Failed random test does not automatically trigger accommodation: A positive drug test alone does not establish a disability or trigger a duty to accommodate. Employers must consider accommodation obligations where an employee has, or is perceived to have, a substance use disorder. Where a substance abuse professional assesses the employee as not having an addiction, and the employee self-identifies as a casual user, the employer may proceed with discipline following a second positive random test.

Gary Clarke, KC is a partner and head of the Employment & Labour Group in Western Canada. Kris Noonan is a partner in the Employment & Labour Group. Justina Sebastiampillai is an associate in the Employment & Labour Group. 

This article was first published on Stikeman Elliott LLP’s Knowledge Hub and originally appeared at www.stikeman.com. All rights reserved.

This publication is intended to convey general information about legal issues and developments as of the indicated date. It does not constitute legal advice and must not be treated or relied on as such. Please read our full disclaimer at www.stikeman.com/legal-notice

Should you have any questions with respect to the employment matters addressed in this decision, please do not hesitate to contact a member of our Employment & Labour Group.

DISCLAIMER: This publication is intended to convey general information about legal issues and developments as of the indicated date. It does not constitute legal advice and must not be treated or relied on as such. Please read our full disclaimer at www.stikeman.com/legal-notice